Does anyone know of any good tutorial sites for threading and multithreading? I am having trouble getting my threads under control, and being able to do things like suspend, resume, and generally everything else excpet creating and running them.

Any good books that you'd recommend?

I tried the multi-thread incrementer and I cannot get the threads to run at the same time.

I wrote a class for handling the threads and calling the class, but it doesn't work. The threads are still executing in order.

Here are my results (keep in mind my function in main puts a 10 delay on the even threads):

Thread Handle: 184 Thread ID: 5132 Thread Param: 0
Exit Time: 6:6:55:930

Thread Handle: 180 Thread ID: 3120 Thread Param: 1
Exit Time: 6:6:55:930

Thread Handle: 188 Thread ID: 4512 Thread Param: 2
Exit Time: 6:7:5:946

Thread Handle: 192 Thread ID: 3444 Thread Param: 3
Exit Time: 6:7:5:946

Thread Handle: 196 Thread ID: 1544 Thread Param: 4
Exit Time: 6:7:15:961

Thread Handle: 200 Thread ID: 5548 Thread Param: 5
Exit Time: 6:7:15:961

Thread Handle: 204 Thread ID: 4464 Thread Param: 6
Exit Time: 6:7:25:976

Thread Handle: 208 Thread ID: 3364 Thread Param: 7
Exit Time: 6:7:25:976

Thread Handle: 212 Thread ID: 2516 Thread Param: 8
Exit Time: 6:7:35:991

Thread Handle: 216 Thread ID: 3432 Thread Param: 9
Exit Time: 6:7:35:991

The inc value: 1000000

Time = H:M:S:MS

There is more to this class, but this is doing everything so I'm just posting this:

MyThread::MyThread(int param_in, LPTHREAD_START_ROUTINE fp, DWORD(*run_func)(int, HANDLE, DWORD))
{
param = param_in;
thread_h = CreateThread(NULL, 0, fp, ¶m, CREATE_SUSPENDED, &thread_id);
(*run_func)(param, thread_h, thread_id); //Run function from pointer
if(num_threads == NULL){num_threads=1;}
else{++num_threads;}
}

Thread object constructor loop:

for(int x = 0; x < 10; ++x)
{
TryEnterCriticalSection(&cs_myThread);
threads[x] = new MyThread(x, (LPTHREAD_START_ROUTINE)ThreadFunction, pThreadFunction); //Param 1: thread object index
LeaveCriticalSection(&cs_myThread);
}

The function that the code runs:

DWORD ThreadFunction(int a, HANDLE h, DWORD id)
{
for(int i = 0; i < 100000; ++i)
{
EnterCriticalSection(&cs_inc);
++inc;
LeaveCriticalSection(&cs_inc);
}

if(a == 0 a == 2 a == 4 a == 6 a ==
{
Sleep(10000);
}

EnterCriticalSection(&cs_out);
GetSystemTime(&st);
outfile << "Thread Handle: " << (int)h << " Thread ID: " << (int)id << " Thread Param: " << a << endl;
outfile << "Exit Time: " << st.wHour << ":" << st.wMinute << ":" << st.wSecond << ":" << st.wMilliseconds << endl << endl;
LeaveCriticalSection(&cs_out);

return 0;
}

The problem:

The reason for the timer is to slow some of the threads done...therefore the faster threads, if running at the same time, will finish before the others. From the output, even without the timer, they are running one after another.

I guess my question is, how do we bypass the wait for return process?

One other thing, I know that threads can be tempermental, if I try to get any information about the thread object from the class, I get an access violation and the app crashes. This happens with the critical sections. Ex. threads[1]->GetThreadHandle() will crash the app...this happens even when ECS/LCS encapsulates the threads[];

Initially I was using '0' but that would crash the application. The problem I was having was that I thought that assigning a function to a thread meant that anytime a that that function was called, it would only run on the thread assigned to run it.

Ok, I'll check those out.

I figured out what the problem was with my simplest version. The main thread was racing through my final output statements resulting in an incorrect inc value. I put a sleep before those outputs and it works fine.

A couple other questions, the thread functions like Resume, Suspend, SetPriority, and so on, all return with a failed state when I try to use them... When and where should these be called? What access rights, if any, does a thread need to make changes to another thread?

Thats what I was thinking, but since I was looking into adding threads I wanted to find out how the different functions worked. When I was receiving the function failure messages, I was calling them from the spawning thread.

Does anyone know when C++ 11 is going to be released for free?

I am having issues with Access Violations with my basic multi-thread graphics engine and I am not sure why. My program runs, keyboard and mouse input works, but the 3D render is only the backround color. I tried using PIX but it loads the app and then closes with no captures.

Error:

Unhandled exception at 0x774415de in Ursa Major.exe: 0xC0000005: Access violation reading location 0xfeef0066.
[frames below may be incorrect and/or missing, no symbols loaded for ntdll.dll]

The access violation points to the UpdateResources call.

// Update variables that change once per frame
EnterCriticalSection(&cs_gView);
cbnc.mView = g_View; // Critical Section Memory Access: g_View
g_pImmediateContext->UpdateSubresource( g_pCBNeverChanges, 0, NULL, &cbnc, 0, 0 );
LeaveCriticalSection(&cs_gView);

I checked the address of g_View and the address of cbnc being sent to D3D and they are different + I am using CS's in render and the g_View matrix update.

What could be the problem?

I used the error logging with PIX and found out it was a problem the TextureRV and the Constant Buffer for the ProjMatrix.

I fixed the Texture problem but am stuck on the access violation problem. As you suggested, it goes away when only using thread-main.

My program is now Single or Multithreaded. Thanks for the tip.